The Dominator.

Han-cheol and his buddies, Geon-mo and Min-ho, want to be the dominators of 11th grade. He gets rid of likely candidates of the 11th grade one by one. One of his opponents is Sang-gil and after school one day, they decide to fight behind an alley. The fight ends with the police appearing, and while the result is inconclusive, they each realize how good their opponent is.